﻿/*************************************************************************************

   Extended WPF Toolkit

   Copyright (C) 2007-2013 Xceed Software Inc.

   This program is provided to you under the terms of the Microsoft Public
   License (Ms-PL) as published at http://wpftoolkit.codeplex.com/license 

   For more features, controls, and fast professional support,
   pick up the Plus Edition at http://xceed.com/wpf_toolkit

   Stay informed: follow @datagrid on Twitter or Like http://facebook.com/datagrids

  ***********************************************************************************/

using System.Windows;
using System.Windows.Media;

namespace Xceed.Wpf.AvalonDock.Controls
{
  internal static class TransformExtensions
  {
    public static Point PointToScreenDPI( this Visual visual, Point pt )
    {
      Point resultPt = visual.PointToScreen( pt );
      return TransformToDeviceDPI( visual, resultPt );
    }

    public static Point PointToScreenDPIWithoutFlowDirection( this FrameworkElement element, Point point )
    {
      if( FrameworkElement.GetFlowDirection( element ) == FlowDirection.RightToLeft )
      {
        var actualSize = element.TransformActualSizeToAncestor();
        Point leftToRightPoint = new Point(
            actualSize.Width - point.X,
            point.Y );
        return element.PointToScreenDPI( leftToRightPoint );
      }

      return element.PointToScreenDPI( point );
    }

    public static Rect GetScreenArea( this FrameworkElement element )
    {
      //    return new Rect(element.PointToScreenDPI(new Point()),
      //        element.TransformActualSizeToAncestor());
      //}

      //public static Rect GetScreenAreaWithoutFlowDirection(this FrameworkElement element)
      //{
      var point = element.PointToScreenDPI( new Point() );
      if( FrameworkElement.GetFlowDirection( element ) == FlowDirection.RightToLeft )
      {
        var actualSize = element.TransformActualSizeToAncestor();
        Point leftToRightPoint = new Point(
            actualSize.Width - point.X,
            point.Y );
        return new Rect( leftToRightPoint,
            actualSize );
      }

      return new Rect( point,
          element.TransformActualSizeToAncestor() );
    }

    public static Point TransformToDeviceDPI( this Visual visual, Point pt )
    {
      Matrix m = PresentationSource.FromVisual( visual ).CompositionTarget.TransformToDevice;
      return new Point( pt.X / m.M11, pt.Y / m.M22 );
    }

    public static Size TransformFromDeviceDPI( this Visual visual, Size size )
    {
      Matrix m = PresentationSource.FromVisual( visual ).CompositionTarget.TransformToDevice;
      return new Size( size.Width * m.M11, size.Height * m.M22 );
    }

    public static Point TransformFromDeviceDPI( this Visual visual, Point pt )
    {
      Matrix m = PresentationSource.FromVisual( visual ).CompositionTarget.TransformToDevice;
      return new Point( pt.X * m.M11, pt.Y * m.M22 );
    }

    public static bool CanTransform( this Visual visual )
    {
      return PresentationSource.FromVisual( visual ) != null;
    }

    public static Size TransformActualSizeToAncestor( this FrameworkElement element )
    {
      if( PresentationSource.FromVisual( element ) == null )
        return new Size( element.ActualWidth, element.ActualHeight );

      var parentWindow = PresentationSource.FromVisual( element ).RootVisual;
      var transformToWindow = element.TransformToAncestor( parentWindow );
      return transformToWindow.TransformBounds( new Rect( 0, 0, element.ActualWidth, element.ActualHeight ) ).Size;
    }

    public static Size TransformSizeToAncestor( this FrameworkElement element, Size sizeToTransform )
    {
      if( PresentationSource.FromVisual( element ) == null )
        return sizeToTransform;

      var parentWindow = PresentationSource.FromVisual( element ).RootVisual;
      var transformToWindow = element.TransformToAncestor( parentWindow );
      return transformToWindow.TransformBounds( new Rect( 0, 0, sizeToTransform.Width, sizeToTransform.Height ) ).Size;
    }

    public static GeneralTransform TansformToAncestor( this FrameworkElement element )
    {
      if( PresentationSource.FromVisual( element ) == null )
        return new MatrixTransform( Matrix.Identity );

      var parentWindow = PresentationSource.FromVisual( element ).RootVisual;
      return element.TransformToAncestor( parentWindow );
    }

  }
}
